Screw driver



B. 'w. SWEET sREw 'Dx1vER- Filed July 5, 1925 July 31,1928..

IIIIIIIIIIIIIIIIIIII j j `line 2-2 ofFig. 1; Fig. 3 is an enlarged Patented July 31, 1928.

UNITED STATES PATENT Y orifice.

BURTON W. SWEET, ORCLRVELAND, OHIO, AssIGNoR 'ro Y'ruis vAN'ijoRN ELECTRIC TOOL COMPANY, or CLEVELAND, curo.

SCREW DRIVER.

Application filed July 3, 1925. Serial No'. 41,453.

This invention relates to portable hand tools and particularly to portable electrically d riven screw drivers.

One feature of the invention relates to the 6 control and its arrangement whereby it is nections between the switch and'motor are.

re-established when the vend cap is replaced. Other features of -the invention will be brought out more in detail in the. following description, drawings and claims.

Referring to the drawings, Fig.' 1 is a side elevation `of a tool constructed according to my invention, with parts broken away to show the control switch and the electrical arrangement; Fig. 2 is a'section upon the section of the part showing the main spindle and clutch mechanism; Fig. 4 is an enlarged 'detail' yview in elevation showing the clutch; Fig. 5 is a section looking at the bit clutch Amember; .and Fig. 6 is a `section looking at the end of the spindle clutch member.`

In the arrangement shown, 1 represents the main motor casing which receives the motor field winding 2. Said casing is provided on one side, which we will assume is the bottom, with a junction block housing 3 provided with a cross strip 4 to which` is suitably secured an insulating junction block 5 provided with a. spring connection clip 6 connected by a wire 7 to the motor. Another connecting clip 6a is also -mounted on this block 5 and is in turn electrically connected to a contact strip 8 which is adapted for engagement with a suitable contact carried by the handle, as will appear. The block 5 is still further provide-d with another contact strip 9. Both of these strips 8 and 9 project beyond the housing 3, as shown in Figs. 1 and 2. The contact 9 is connected to the other wire 10 of the motor circuit so that when thecircuit is completed between these strips 8 and 9, current will be supplied to the motor. The construction of the armature and eld are unimportant, except that the usual commutator projects beyond the motor casing 1, as is usual, and cooperates with a pair of brushesll, one being shown in Fig. 1. The commutator and the brushes are all housed in a rear cap 12 Y finger of the operator.

secured tothe motor casing. vThis cap` is provided with an insulating block 15 provided with two handle leaf contacts 16, each 'having a bent spring end portion 17 for engagement with the projecting portions of the leaf contacts 8 and 9, as shown clearly in Figs. 1 and 2. The end cap 12 is provided with an upper solid rearwardly .eX- tending portion .18 and a lower hollow e-X- tension 1 9, both of which merging into al half-round handle origrippingfp'ortion 2O adapt-ed to receive the switch mechanism, the Agjinplete handle being formed by the cover The switch mechanism includes an insulating block 21 supported upon a mounting 22 and provided with spaced leaf contacts 23 and 24 connected by leads 25 and 26 respectively, tothe handle leaf contacts 16. The mounting 22 at its upper end is provided with supporting ears 25V carrying a pivot 26" supporting :the movable lContact lever 27 provided with abridge memberi28 adapted for engagement between the contacts 23 and 24 to complete the circuit there through. The contact lever 27 projects Vto the rear of pivot 26 and is there connected to a toggle arm 29 provided with a pin3O engaging in a slot 31 in a suitable bracket 32 carried by a reciprocating controller or finger piece 33 sli'dably mounted in the handle portion and provided with a downwardly extending portion 34 to be grasped by the The opposite end of this linger piece 33 is provided with a button 35 for manipulatingl the switch in the opposite direction, as will appear. The pin30 is connected by a spring 36 with the pivot 26 of the contact lever 27 and the arrangement is such that when the finger piece 34, for example, as shown in Fig. 1, is moved toward the right, carrying with it the pin 30, the spring 36 will be moved beyond the straight line position of the levers 27 and 29 with the result that the switch will be thrown into engagement with the contacts 23 and 24 withl a quick snap and the circuit will be closed. When pressure is brought to bear upon the button 35 in the opposite direction, the parts will be moved contrawi'se, the switch will be released and the circuit will be broken.

Secured tothe main motor casing 1 is a gear housing 37 provided with an extension 38 adapted to receive a main spindle bearn ing 39 in which is mounted the main spindle 40. This spindle is driven by a gear 4l meshing with a pinion 42 which forms ak part of. a compound gear including another gear 43 meshing with thel motor pinion 44'.

The extension 38 extends beyond the bearing 39 to receive the work spindle clutch mem '49 off the tool clutch member 50 which is provided with opposed lugs 51 of substantiallyf the shape ofthe recesses or notches 46'. The tool` clutch member 50 is of sleeve form somewhat larger than the main spindle extension48fand receives withinA it a bushing 52' surrounding a still further reduced spindle portion. 48a' and providedv with aV stop flange 53 projecting beyondV the circumference of the extension 48. This bushing flange 53 engages a shoulder 55a between the two reduced spindle portions 48, 48- and isv held inpl'ace by a suitable lscrew 54' secured 'within'the outer end off the spindle portion 48a. The flange 53 also serves to engage within' the shoulde-r 55` formed near the clutch end of the tool clutch member 50 and serves to limit the outward movement of the clutch. The tool clutch is internally threaded at its outer end asat 56 and receives the threaded shank 57 of a tool socket 58 in turn internally threaded at 59 to receive the threaded shank 60v of the tool' or screw driver bit 6l. A spring 62 surrounds the bushing 52' and thrusts on the one end against the vstop 53 and on the other against portion 57 of the socket member 58 causing all of these parts, together with the tool clutch member to be forced outward resulting in the disengagement of the clutch.

Having describedv my invention, I claim:

1'. In amotor hand tool, a main casing, a motor therein, a work spindle driven thereby, a suitable cable connection for the supply cable leading to the tool, a junction block for the motor terminals and the cable connectie-n andr includingv switch contacts, and a combined end cap and handle removably secured to the casing and provided with a controlling switch and suitable contacts adapted to cooperate with the contacts of the junction block whereby the end cap and handle may be removed 'without disturbing theA electrical connectionsto the motor.

2. In a motor hand tool, a main casing,. a motor within the same with its commutator extending beyond said casing, a junction block housing extending from.' said casing, a junction block within said; housing Wire-d to the incoming cable and to the motor, switch contacts carried'l by said junction blocks and extending from the motor casin@ an end cap covering the exposed com- 3 mitat'or of'. the motor andprovided with a housing portion housing said switch contacts of the junction block, a Yhandle carried.v

by said end cap, a` switch within the handle, a contact block mountedk in the housing of the end cap, and yielding contacts carried therebykto cooperate with the switch contacts ofv the junction block.

In testimony whereof I hereby ai'lix my signature. f

BUn/Ton. w. SWEET; 

